Question
I live in Brownsville, Texas and there is mostly clay soil.  We added topsoil a few years ago and now it is time to do something again as the grass is not doing well.  We have floratam grass and the soil they brought is from the river.  Is this good soil for the grass we have or do we need to get topsoil?  Please respond asap as the soil is ready to be spread out on my lawn and I don't want it to kill my grass.

Answer
Hi Esther, the correct thing to do when renovating a lawn is spread your soil and then till it into the existing soil 6 inches deep for a uniform consistency.  This requires either removing your sod or seeding/sprigging/sodding.  Spreading loose soil on top of clay makes watering difficult.
Clay is not bad, if the grass is suffering, I'd first look to pH and soil fertility as the culprit and since you have the soil, consider spreading a very thin layer of soil/compost on the surface and just using a soil aerator to incorporate it.
Jim